Solar Panels in Monsoon Season: How Much Do They Actually Generate?
Learn how solar panels perform during monsoon season in India. Understand real production rates, impact on savings, and why monsoon isn't a barrier to solar.
Murthy Pedapalli
12/6/20254 min read
One of the most common concerns when considering solar panels in India is their performance during the monsoon season. Many people wonder: Will my solar panels work when it rains? How much will my electricity generation drop? Will I still save money?
These are legitimate concerns, but the good news is that monsoon season doesn't eliminate solar benefits. In fact, understanding how solar panels perform during monsoons helps you make better decisions about your installation timing and system size.
How Do Solar Panels Work in Cloudy Weather?
Solar panels don't require direct sunlight to generate electricity. They work on light energy, not heat. Even on cloudy days, diffuse light from the sky is captured by the solar cells, producing electricity.
Energy generation in different weather conditions:
Clear sunny days: 100% capacity
Partly cloudy days: 70-80% capacity
Heavily cloudy days: 30-40% capacity
Light rain: 20-30% capacity
Heavy rain: 5-10% capacity
The key insight: Solar panels continue generating electricity even without direct sunlight, though at reduced efficiency.
Monsoon Production Reality in India
During the Indian monsoon season (June-September), cloud cover increases significantly. However, production doesn't stop entirely. Here's what actually happens:
Production Reduction During Monsoon:
Average reduction: 40-60% compared to summer
Daily generation: 3-4 kWh per kW of installed capacity (vs. 5-6 kWh in summer)
Impact on annual generation: Monsoon accounts for 15-20% of annual output
Why isn't it worse?
India still receives significant diffuse light even during clouds
Clouds are temporary – many days have partial cloud cover, not all-day clouds
Panel technology improves – modern panels capture diffuse light better than older panels
Panels stay clean – rain naturally cleans panels, improving efficiency
Regional Variations in Monsoon Impact
High Impact Regions (40-50% reduction):
Western coast (Kerala, Karnataka, Goa)
Northeast (Assam, Meghalaya)
Coastal Tamil Nadu
Moderate Impact Regions (30-40% reduction):
Maharashtra, Telangana
Northern Coastal areas
Parts of Karnataka
Low Impact Regions (20-30% reduction):
Delhi, Rajasthan, Punjab (drier monsoons)
Interior Andhra Pradesh
Portions of Gujarat
Why Your Annual Savings Aren't Significantly Affected
The secret is that summer generation more than compensates for monsoon reduction.
Typical Annual Pattern:
SeasonMonthsProduction% of AnnualSummerMar-May45%High generation offsets other seasonsPost-MonsoonOct-Nov20%Good generation as skies clearWinterDec-Feb15%Lower but consistentMonsoonJun-Sep20%Lower but still significant
Even with 20% of annual output during monsoon, your total yearly generation remains substantial.
Example: How Monsoon Affects Your Savings
3 kW System Annual Performance:
Summer (3 months):
Daily generation: 18 kWh
Monthly generation: 540 kWh
Summer total: 1,620 kWh
Monsoon (4 months):
Daily generation: 9 kWh (50% reduction)
Monthly generation: 270 kWh
Monsoon total: 1,080 kWh
Post-Monsoon & Winter (5 months):
Daily generation: 12 kWh
Monthly generation: 360 kWh
Post-monsoon total: 1,800 kWh
Annual Total: 4,500 kWh
Your Savings:
Electricity rate: ₹8 per unit
Annual value of generation: ₹36,000
Monthly average savings: ₹3,000
Even accounting for monsoon, substantial savings!
When Should You Install Solar Panels?
Many people ask: "Should I wait until after monsoon to install?"
Answer: No, here's why:
Immediate benefits – You start generating electricity even on cloudy monsoon days
Net metering works year-round – Excess generation gets credited during monsoon too
Testing period – Monsoon is ideal for testing system reliability
Faster payback – Earlier installation means payback starts sooner
Installation wait times – Post-monsoon (October-November) has longer waiting periods due to high demand
Best installation window: April-May or July-August. Even monsoon installations are productive.
Does Heavy Rain Damage Solar Panels?
Short answer: No. Solar panels are specifically designed to withstand weather conditions, including heavy rain.
Why rain isn't a problem:
Waterproof design: Panels are sealed with weatherproof materials
Tested standards: All ISI-certified panels must pass water resistance tests
Mounting systems designed for heavy rain and wind loads
Self-cleaning: Rain naturally washes dust and debris, improving efficiency
Historical reliability: Solar panels in Kerala, which receives extreme rain, work perfectly
Safety during lightning:
Proper earthing/grounding is essential (included in professional installation)
Surge protection devices protect inverters and batteries
Never touch electrical components during storms
Maximizing Performance During Monsoon
Tips to maintain optimal generation even during monsoon:
Professional Installation with Proper Tilt Angle
Correct angle ensures rain runoff and reduces water pooling
SolarClub engineers design 15-25° angle optimal for your location
Regular Cleaning
Even in monsoon, clean panels quarterly
Use soft brush and distilled water to avoid mineral deposits
Avoid harsh cleaning during heavy rain
Weather Monitoring
Use your monitoring app to track generation
Lower generation on specific days is normal and expected
Look for patterns – not individual low days
Battery Backup Planning
If you have battery storage, it smooths out monsoon variability
Store excess generation from sunny monsoon days
Battery usage increases during continuous rain periods
Hybrid System Advantage
Grid connection provides backup during heavy monsoon days
Battery + Grid combination gives 24/7 power reliability
Understanding Your Monitoring App During Monsoon
When checking your monitoring app during monsoon, expect to see:
Normal patterns:
Gradual generation increase from sunrise
Mid-day peak (even on cloudy days)
Gradual decrease toward sunset
Lower daily totals on heavily cloudy days
What indicates a problem:
Zero generation for extended periods (>24 hours)
Generation less than 30% of monsoon average
System offline/disconnected indicator
When to Be Concerned About Your System
Monsoon is actually a good time to identify installation issues:
Monitor for these problems:
Water leakage around junction boxes
Loose mounting components (not visible before monsoon)
Inverter power loss during heavy rain
Battery swelling or leaking
Frequent inverter shutdowns
Contact your installer immediately if you notice any of these during monsoon.
Frequently Asked Questions
Q: Should I turn off my system during monsoon?
A: No. Let it run continuously. Shutdowns don't improve safety. Proper grounding provides protection.
Q: Will monsoon reduce my battery lifespan?
A: Slightly, due to increased charging cycles. But overall lifespan remains 5-7 years with quality batteries.
Q: Can I get net metering credit during monsoon?
A: Yes! Any excess generation gets credited at the same rate as other seasons.
Q: Is it safe to install during active monsoon rain?
A: Not recommended. Wait for dry spells. Your installer will advise proper timing.
Conclusion
Monsoon season should not deter you from investing in solar panels. While generation drops 40-60% during monsoon months, the overall annual benefit remains substantial because summer generation compensates significantly.
In India, where monsoon is predictable and temporary, solar systems are specifically designed to handle it. Your investment in solar panels continues paying dividends even during the rainy season.
The real question isn't whether to install solar before or during monsoon. The question is: how much longer will you wait to start saving money?
Contact SolarClub today for monsoon-proof solar installation with proper design and grounding for your location.